Hello,
I have copied the Grid Filtering example - grid-filter-local.js -
in to a local file and made 0 changes - apart from the urls, which
are referencing actions in a controller.
The grid is correctly displayed but when I select a menu item
to see the filter option, the following message/stack trace is
obtained:

The exact code I'm using is below also:
An example of data returned from the controller is: { "success": true, "total": 1, "data": {"id":1,"company":"Ed","price":4,"size":"small","date":"01/01/2012","visible":true}}

// use a factory method to reduce code while demonstrating
// that the GridFilter plugin may be configured with or without
// the filter types (the filters may be specified on the column model
var createColumns = function (finish, start) {

Hello,
I resolved this particular error by including the FiltersFeature dependencies.

I am not sure why I needed to do? this since I included the following:
Ext.Loader.setConfig({enabled: true});
Ext.Loader.setPath('Ext.ux', '../extjs/examples/ux');
Ext.require([
'Ext.grid.*',
'Ext.data.*',
'Ext.ux.grid.FiltersFeature',
'Ext.toolbar.Paging'
]);